which plinth/tonearm for TD-124 SME or other

i just scored a Td-124 that i'm looking forward to restoring and i've read a lot of about their potential.

i have two questions.
re: plinth - i have a huge chunk of granite (4" thick) that i rescued from a building demolition in Detroit - and found a granite shop that can cut it and route it for the td-124 table - i'm quite certain it will be heavy - but is there any reason i shouldn't use this as a plinth, vs a good hard wood? i've also read that solid mounting it, or letting it sit flat on the plinth w/o the rubber isolators can produce good results - while i'm not new to the audiophile stuff, i am slowly learning to hear the subtleties that you guys talk about -

2) the tonearm - i was thinking of an SME 3009 - but i'm confused as to which one? the S2, the S3, the S2 improved etc.. I found a decent price on a 3009 S2 Improved, but have heard that it uses a plastic knife-edge bearing -
on ebay, someone sells the cnc bronze replacement for about 30 bucks... is this the big issue with this tonearm? or should i forget about the SME and find something else that will outperform it - or - is a better arm just going to result in diminishing returns for this table??

sorry for the stream of consciousness here - but trying to get a lot answered in one post - thanks
Kind of a tough question to answer..About a year ago I purchased a nice used TD124 Mk1 with SME 3009/2 unimproved
and I went to a DIY Maple ( 1"thick ) plinth and removed the rubber mushrooms ( secured to the plinth from underneath ) and find it to be a great combo..The extra Mass seems to help considerably with performnce..I am not an expert by any means ,but I think the more "Mass" and rigidity you can add the better off you will be..Plenty of info on the Web.....
A sorted TD124 is a top class TT. I've had two over the years and only sold mine when I spent a lot more on a Platine Verdier. If you can get someone to cut the granite for you, then just use that. Use the mushrooms as well to start with. As for arms, well that's a complex call. You have to view the arm/cart/phono stage as one item. What sort of budget do you have and what's the rest of your system and musical tastes?
well - i have a Grado Master Statement cartridge and the Grado PH-1 -
they are currently mounted in my Td-135 and sound great -but i'm not sure the original thorens arm on that TT is allowing that cart to work its best.

so - lets assume i use the granite plinth, and the grado cart/PH-1

which arm would you suggest? i envision spending somewhere between 500-1000 - any more than that and it would be beyond my budget at this point.